The screws are made of galvanized steel to protect against corrosion. When there are no screws and plugs left, you can use the box for storing small things. http://www.ikea.com/th/en/images/products/fixa-piece-screw-and-plug-set__0114490_PE266983_S4.JPGFIXA 260-piece screw and plug sethttp://www.ikea.com/th/en/catalog/products/20169248/201.692.48THB 249